Monitoring refers generally to an act of watching and checking a situation for a period of time in order to discover some element about it. A situation, as such, refers to a set of things that are happening and/or the conditions that exist at a particular time and place. In the following, a set of things that are happening and/or the conditions that exist are jointly called as impulses. A monitoring module is an apparatus that can be positioned temporarily or permanently to a particular place to detect a set of impulses, and to generate impulse signals representing them. These impulse signals may be transferred to one or more data repositories for later use, or they may be used to trigger alarms, for example in a designated response centre. The task of such centre is to analyse the alarms and initiate appropriate measures needed to appropriately intervene a situation or influence a developed condition.
Monitoring has various commercial and industrial applications. A significant number of security systems are concerned with monitoring the environment. In addition to various burglar alarm systems there are meters for measuring consumption of utilities such as gas and electricity. There are also monitoring systems to watch over dangerous substances, such as fissile materials or hazardous chemicals. Vehicle systems, such as telemetry, taximeters and tachographs are widely used in road and marine transportation. These are only some examples, due to the rapid development of cost-effective wireless technologies; the application of monitoring systems has increased significantly. Also the size of the populations and/or the amount of impulses to be monitored has grown correspondingly.
One of the problems associated with the present monitoring systems is their poor capability to scale from small footprint systems to larger systems that have broader geographical extent and/or larger population. There are some clustered and hierarchic network topologies, which have been developed to dynamically route around obstacles and provide backup routes in case of a network congestion or device failure. However, even in those systems the amount of alarms and complexity of dealing with numerous different types of alarms in the response centre has imposed rigid limitations to the size of the system. In a conventional system that relies on a centralized decision making, the response centre relatively quickly becomes the bottleneck of the system, and any increase in complexity and/or device populations poses a risk to cause overload or delays in reacting to the impulses.
The effects of the increased number of monitoring module population could be compensated by limiting complexity with use of simplified alarm types, but that would obviously diminish the overall performance of the monitoring system. In a simplified system only a few selected happenings and conditions could actually be followed. However, the desire of most user organizations is to have a monitoring tool with which various different impulses could be effectively considered and acted upon.